The present invention relates to a cable reel assembly for electric cables, and particularly, but not exclusively, for reeling up the electric cable of a vacuum cleaner, the cable reel assembly comprising a rotatable drum onto which the electric cable is reeled, an electric motor which is operative for driving the drum in the cable reel-in direction, and a storage battery having a battery charging unit which is connected to the cable in a manner such as to recharge the battery when the cable is connected to a current power source.
In known cable reel assemblies the energy required to reel-in the cable is obtained by means of a spring which is tensioned as the cable is drawn off the drum. These known cable reel assemblies have two serious drawbacks, namely that the cable moves sluggishly when reeled off from the drum, and that some form of braking must be provided, in order to hold in check the speed at which the cable is reeled onto the drum.
Withdrawal of the cable can be made smoother and the cable reel-up speed can be maintained at an essentially constant level, by replacing the spring with an electric motor. The energy required thereof can be taken from a battery, or storage battery (accumulator). In this latter case the battery is recharged, e.g., with the aid of a battery charger which, in the case of a vacuum cleaner, is embodied in the vacuum cleaner itself and which replenishes the battery when the electric cable is plugged into the mains. The aforesaid two drawbacks associated with known spring-biassed cable reel assemblies are not found with motor driven reel assemblies. Furthermore, the use of motor-driven reel assemblies enables much longer cables to be reeled up.
For the purpose of reducing the force required to draw cable from the drum of such cable reel assemblies, it is proposed in the published European Patent Publication Serial No. 0 044 490 that the cable reel assembly is disconnected from the reel drive when drawing cable from the drum, and that an electric motor is used for reeling in cable onto the drum, or that the cable drum is driven by an electric motor, either directly or indirectly, both when reeling off cable from the drum and when reeling cable thereonto.
The advantages afforded by a battery-driven cable reel assembly is that a longer cable can be accommodated, that the cable can be drawn out more easily, since no spring need be tensioned, and that the cable is reeled onto the drum more slowly and more smoothly than would otherwise be the case, therewith reducing wear on the cable and consequently eliminating, for instance, the risk of impact from the cable.